1. Field of the Invention
The present invention relates to an image processing apparatus, method, and program and more particularly, to an image processing apparatus, method and program capable of reducing influence of vibration to an image when the image is picked up by a portable image pickup apparatus.
2. Description of the Related Art
Portable video cameras and digital still cameras have been widely used. In the following description, the video camera will be described as an example. As an example of an object image pickup device used for the video camera, there are charge transfer type object image pickup devices such as a CCD (charge coupled device) sensor and X-Y address type object image pickup device such as a CMOS (complementary metal oxide semiconductor) sensor.
The CMOS sensor has low power consumption and is driven with a single low voltage in comparison with the CCD sensor and driver. In addition, since the CMOS sensor can be easily integrated with peripheral circuits, the CMOS sensor is used for the image processing apparatus such as a video camera.
However, it is difficult to record a high quality moving or still image by using the CMOS sensor as the image pickup device of the image processing apparatus such as a video camera. One of the reasons is that deformation of the picked-up image caused by hand shake occurs. In case of the CCD senor which has been used as an image pickup device of the image processing apparatus, a correction amount required for performing a process for reducing influence of the hand shake is a single value which is calculated based on hand shake information obtained in one field or one frame. In this case, exposure time intervals of all the pixels are equal to each other, and deformation of image does not occur, so that the hand shake can be corrected by using the single value.
In case of the CMOS sensor, an image of an object is picked up by using the following mechanisms, deformation of image caused by the hand shake occurs. The deformation is considered to occur as follows.
In the charge transfer type solid-state image pickup device such as a CCD senor, all the pixels can be exposure at the same time to allow pixel data to be read out. However, in the X-Y address type solid-state image pickup device such as a CMOS sensor, the pixel data are sequentially read out in units of one pixel or one line. In a case where the pixel data are sequentially read out in units of one line, if one image is constructed with 1 to N lines, and if a time of t seconds is taken to read out one line, a time of N×t seconds is taken to read out data of one image.
In other words, from a time that a first line is read out, after a time of about N×t seconds elapses, an N-th line is read out. Due to such a time delay, if vibration such as hand shake is exerted at a time that an image is picked up (when the image data are read out line-by-line), image positions in the first line and the n-th line deviate, so that deformation of the picked-up image may occur.
In order to reduce the deformation of image, a technique for performing vibration removing correction at a time that the vibration such as hand shake is, exerted has been proposed (see Patent Document 1). Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-266322
In addition to the hand shake correction, other processes are also performed in the image processing apparatus such as video camera. Recently, due to increase in the number of pixels and a high accuracy of the video camera, data amount and processed amount thereof increase greatly. For the reason, a required memory capacity increases, so that a processing performance intends to be improved.
Particularly, unlike a still image, it is important to process a moving image in real time. Therefore, in case of the moving picture, a larger memory capacity is required, and a highly-accurate processing performance is required. If a size of signal processes increase greatly, costs and power consumption increase greatly. However, low cost and power consumption is preferable in terms of increase in a driving time. Therefore, it is necessary to reduce costs and power consumption and to efficiently treat a process influencing with the reduction thereof.
The present invention is to efficiently perform a process and reduce costs or power consumption.